It's way more than just a polite greeting. It's a second measure of your vim and vigor.

The way you grip someone's hand may have more meaning than you realize. Researchers from Canada have recently concluded that it may indicate the future of someone's health, as well as their life span.

A study published in the recent issue of the journal The Lancet tested the grip strength of nearly 140,000 adults from 17 different countries who were between 35 and 70 by using a handgrip dynamometer. "The participants were asked to grip the dynamometer three times with each hand," study author Dr. Darrly Leong from the Population Health Research Institute, Hamilton Health Sciences at McMaster University, told Yahoo Health. "The maximum values for each hand were then averaged. Grip strength,n was only measured at their baseline (initial) visit. Thereafter, participants were contacted on an annual basis (for an average of four years) to determine whether they had suffered any of the outcomes that we reported on."

Here's what Leong and his team discovered. For every 5kg decline in grip strength, there was a: 17 percent increased risk of cardiovascular death 17 percent increased risk of non-cardiovascular death 16 percent increased risk of death from any cause 9 percent increased risk of having a stroke 7 percent increased risk of suffering from a heart attackOther life-altering factors, such as age, education level, employment status, physical activity level, and tobacco and alcohol use, were taken into account.

"Grip strength could be an easy and inexpensive test to assess an individual's risk of death and cardiovascular disease," says Leong.However, this is not the first trial that examined the possible underlying meaning of a handshake. A study conducted last year by researchers from the International Institute for Applied Systems Analysis found that a handshake can determine someone's "true" age and education level.

And yes, the firmer, the younger.

"According to hand grip strength, people with high education...feel several years younger compared to people with lower education," study author Sergei Scherbov told the Agency-France-Press (AFP), the international news agency.

The same researchers reviewed other works that studied more than 1 million young Swedish men who took part in a military exam. They concluded that those with a weaker grip were "significantly" more likely to have a shorter lifespan, to be diagnosed with heart disease, suffer from psychological problems, as well as have a higher risk of suicide.

And then there's the importance of a handshake in making a good first impression. Study experts from the Beckman Institute at the University of Illinois found that offering to shake hands, followed by a firm grip, can raise someone's opinion of you. "We found that it not only increases the positive effect toward a favorable interaction, but it also diminishes the impact of a negative impression," lead researcher Sanda Dolcos said in a statement.

Her advice for those looking to charm someone: "I would tell them to be aware of the power of a handshake."